On the other hand there are many people who think that, may be hexagon aquariums are not good for big fish but they are good for small ones. Small fish can swim and can utilize the entire surface area for a bigger and enjoyable swim. Apart from this fact, the second most important thing is hexagonal fish tanks are made up of acrylic. Acrylic aquariums are unbreakable and do not require much maintenance. The most important factor in this is the temperature. Acrylic aquariums are easy to maintain the temperature as compared to the glass ones. So by this we can say that if you want to keep a hexagonal tank then it is better to have small fish and that too less in number.